JP5772206B2 - Linear motion guide device - Google Patents

Description

  The present invention relates to a linear motion guide device.

  A conventional linear guide device has a guide rail having a rolling element rolling groove extending in the axial direction on the outer surface, a rolling element rolling groove facing the rolling element rolling groove of the guide rail, and a relative movement in the axial direction. A plurality of sliders attached to the guide rails and capable of rolling in a rolling element rolling path formed between the rolling element rolling grooves of the guide rail and the rolling element rolling grooves of the slider. And a slider is movable in the axial direction along the guide rail through the rolling of the rolling element in the rolling element rolling path. In general, the rolling element rolling paths are symmetrically arranged on both sides of the guide rail. In the present invention, when the linear motion guide device is viewed from the axial end portion side, both sides with the center axis of the guide rail as the center of symmetry are set to the left and right.

  Lubricants such as lubricating oil and grease are supplied to the rolling elements in the rolling element rolling path for lubrication. In other words, the oil supply passage branching left and right from the oil supply port provided at the substantially central position in the left-right direction of the slider leads to the left and right rolling element rolling passages, and the lubricant introduced into the oil supply port passes through the oil supply passage and moves to the left and right. It is supplied to the rolling element rolling path. When the linear motion guide device having such an oil supply path is installed horizontally, the lubricant is supplied almost evenly to the left and right rolling element rolling paths.

  However, when the linear motion guide device is installed in an inclined posture that causes a height difference between the left and right rolling element rolling paths, the lubricant flows downward due to its own weight, The lower rolling element rolling path is supplied with a larger amount of lubricant than usual (when horizontal), and the higher rolling element rolling path is supplied with a smaller amount of lubricant than usual, depending on the inclination angle. There is also a possibility that almost no lubricant is supplied. As a result, there is a risk that the lubricant will be insufficient in the rolling element rolling path on the higher side, causing problems such as seizure.

Therefore, even when installed in an inclined posture that causes a height difference between the left and right rolling element rolling paths, the linear motion guide is supplied with the lubricant almost evenly to the left and right rolling element rolling paths. A device has been proposed.
For example, Patent Document 1 describes a linear motion guide device that includes a lubricant supply amount adjustment unit that operates by gravity and automatically adjusts the supply amount of lubricant to a rolling element rolling path. That is, when the weight moves under the influence of gravity, the cross-sectional area of the oil supply passage changes and the supply amount of the lubricant is adjusted. The weight is supported by a spring so that the moving distance of the weight (the size of the cross-sectional area of the oil supply passage) changes according to the magnitude of the inclination angle.

  Patent Document 2 describes a linear motion guide device installed sideways, that is, a linear motion guide device installed such that left and right rolling element rolling paths are arranged vertically. In this linear motion guide device, since the lubricating oil is difficult to be supplied to the rolling element rolling path disposed on the upper side, a lubricating oil holding body is provided inside the oil supply path leading to the rolling element rolling path disposed on the upper side. A certain felt is arranged so that the lubricating oil absorbed in the felt is supplied to the rolling element rolling path.

JP 2009-156376 A JP 2007-100956 A

However, in the linear motion guide device described in Patent Document 1, if the lubricant enters the portion where the spring is disposed, the lubricant supply amount adjusting unit may not operate normally. Further, since the mechanism of the lubricant supply amount adjusting unit is complicated, a simpler one has been demanded.
Further, if it is a lubricating oil, it is absorbed by the felt, but since the grease is difficult to be absorbed by the felt, it is difficult to apply the grease as a lubricant for the linear motion guide device described in Patent Document 2.

  Therefore, the present invention solves the above-described problems of the prior art, and each rolling element rolling even in the case of taking an inclined posture in which a height difference is generated between a plurality of rolling element rolling paths. In addition to the difference in the amount of lubricant supplied to the road being less likely to occur, the mechanism for adjusting the amount of lubricant is simple and less likely to cause malfunction, and both linear oil and grease can be used as a lubricant. It is an issue to provide.

  In order to solve the above-described problems, an aspect of the present invention has the following configuration. That is, the linear motion guide device according to one aspect of the present invention includes a guide rail having a rolling element raceway surface extending in the axial direction, a rolling element raceway surface facing the rolling element raceway surface of the guide rail, and in the axial direction. A slider attached to the guide rail so as to be relatively movable, and a rolling element raceway surface formed between the rolling element raceway surface of the guide rail and the rolling element raceway surface of the slider. A plurality of rolling elements, an oil supply path for supplying a lubricant introduced from a lubricant inlet provided in the slider to the rolling element rolling path, and a downstream side of the lubricant inlet in the oil supply path A valve provided at a position, and the valve is in an open state when the pressure of the lubricant introduced into a portion of the oil supply passage between the lubricant introduction port and the valve is equal to or greater than a predetermined value. And the lubricant is passed downstream. Together they have become so that, wherein said pressure is in higher as the opening degree increases.

  In such a linear guide device according to one aspect of the present invention, the valve is made of an elastic material, and the valve is elastically deformed and opened by the pressure, and the higher the pressure, the higher the pressure. It is preferable that the degree of deformation of the valve is large and the degree of opening of the valve is large.

  The linear motion guide device according to the present invention includes a valve that is opened when the pressure of the introduced lubricant is equal to or higher than a predetermined value, so that there is a difference in height between a plurality of rolling element rolling paths. Even when taking an inclined posture, the difference in the amount of lubricant supplied to each rolling element rolling path is less likely to occur, and the adjustment mechanism for the amount of lubricant is simple and less likely to cause malfunction. Any grease can be used as a lubricant.

It is a perspective view which shows the structure of one Embodiment of the linear guide apparatus which concerns on this invention. It is the front view which looked at the linear motion guide apparatus of FIG. 1 from the axial direction edge part side. It is AA sectional drawing of FIG. It is the figure which abbreviate | omitted the return guide and showed the back surface of the end cap. It is a front view of a return guide. It is a perspective view of an end cap in the state where a return guide is attached. It is the figure which showed the back surface of the end cap in the state equipped with the valve. It is a perspective view of a valve. It is BB sectional drawing of FIG. It is a figure explaining operation | movement of a valve.

  An embodiment of a linear motion guide device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the structure of an embodiment of a linear motion guide device according to the present invention. FIG. 2 is a front view of the linear motion guide device of FIG. 1 as viewed from the axial end side (however, the end cap is omitted). 3 is a cross-sectional view taken along the line AA of FIG. 2, and is a partial cross-sectional view showing a rolling element circulation path of the linear motion guide device of FIG.

  In the drawings referred to in the following description, the same or corresponding parts are denoted by the same reference numerals. In the following description, “cross section” means a cross section when cut along a plane perpendicular to the axial direction unless otherwise specified. Furthermore, terms indicating directions such as up, down, left, and right in the following description mean the respective directions in FIG. 2 for convenience of description unless otherwise specified.

  On a substantially square guide rail 1 extending in the axial direction, a slider 2 having a substantially U-shaped cross section is assembled so as to be movable in the axial direction. This guide rail 1 has four outer surfaces extending in the axial direction in addition to both axial end surfaces, but on the ridge line portion where the left and right side surfaces 1a, 1a and the upper surface 1b that are parallel among the four outer surfaces intersect. Are formed with rolling element rolling grooves 10 and 10 (corresponding to the rolling element raceway surface, which is a constituent element of the present invention), each of which is formed of a concave groove having a substantially arc-shaped cross section extending in the axial direction. Rolling element rolling grooves 10 and 10 each formed of a concave groove having a substantially semicircular cross section extending in the axial direction are formed at the center in the vertical direction of the left and right side surfaces 1a and 1a.

  The slider 2 includes a flat plate portion 7 along the upper surface 1b of the four outer surfaces of the guide rail 1, and two arm portions 6 and 6 extending downward from the left and right side portions of the flat plate portion 7 along the side surface 1a. Since the angle between the flat plate portion 7 and the arm portions 6 and 6 is a right angle, the cross-sectional shape of the slider 2 is substantially U-shaped. The slider 2 is movably attached to the guide rail 1 such that the guide rail 1 is sandwiched between the arms 6 and 6.

  Such a slider 2 includes a slider main body 2A and end caps 2B and 2B that are detachably attached to both end portions in the axial direction. Furthermore, side seals 5 and 5 are attached to both end portions of the slider 2 (end surfaces of the end caps 2B) to seal the axially open portion of the gap between the guide rail 1 and the slider 2. Under the slider 2, under seals 8 and 8 are attached to seal the downward opening portion of the opening portion of the gap between the guide rail 1 and the slider 2. The side seals 5 and 5 and the under seals 8 and 8 prevent foreign matter from entering the gap from the outside and outflow of the lubricant from the gap to the outside.

  Further, the corners on the inner side surfaces of the left and right arms 6 and 6 of the slider body 2A and the central portion in the vertical direction are substantially semicircular in cross section facing the rolling element rolling grooves 10, 10, 10, 10 of the guide rail 1. Rolling element rolling grooves 11, 11, 11, 11 (corresponding to the rolling element raceway surface, which is a constituent element of the present invention). And between the rolling element rolling grooves 10, 10, 10, 10 of the guide rail 1 and the rolling element rolling grooves 11, 11, 11, 11 of the slider 2, the rolling element rolling path 13, having a substantially circular cross section, 13, 13 and 13 are formed, respectively, and these rolling element rolling paths 13, 13, 13, and 13 extend in the axial direction.

A plurality of rolling elements 3 are slidably loaded in the rolling element rolling paths 13, and the slider 2 moves in the axial direction along the guide rail 1 through the rolling of these rolling elements 3. It is supposed to be. In addition, the kind of rolling element 3 is not limited to a sphere, A roller may be sufficient. Further, the number of rolling element rolling grooves 10 and 11 provided in the guide rail 1 and the slider 2 is not limited to two rows on one side, and may be one row on one side or three rows or more, for example. Furthermore, the cross-sectional shape of the rolling element rolling grooves 10 and 11 may be an arc shape formed of a single arc as described above, but is substantially V-shaped (Gothic arc shape) formed by combining two arcs having different centers of curvature. Groove).
Furthermore, the slider 2 penetrates in the axial direction in parallel with the rolling element rolling paths 13, 13, 13, 13 in the upper and lower portions of the thick portions of the left and right arms 6 and 6 of the slider body 2A. A straight path 14, 14, 14, 14 comprising a straight hole having a circular cross section is provided.

On the other hand, the end cap 2B is made of, for example, an injection molded product of a resin material, and has a substantially U-shaped cross section. In addition, on the left and right sides of the back surface of the end cap 2B (the contact surface with the slider body 2A), a curved path 16 having a circular cross-section and a half donut shape is formed in two upper and lower stages. When the end cap 2B is attached to the slider body 2A, the rolling element rolling path 13 and the linear path 14 are communicated with each other by the curved path 16.
The linear path 14 and the curved paths 16 and 16 at both ends constitute a rolling element return path 17 that feeds the rolling element 3 from the end point of the rolling element rolling path 13 to the starting point, and the rolling element rolling path 13 and the rolling element. The return path 17 constitutes a substantially annular rolling element circulation path. The substantially annular rolling element circulation path is formed on both the left and right sides of the guide rail 1.

  When the slider 2 assembled to the guide rail 1 moves in the axial direction along the guide rail 1, the rolling element 3 loaded in the rolling element rolling path 13 rolls in the rolling element rolling path 13. However, it moves in the same direction as the slider 2 with respect to the guide rail 1. When the rolling element 3 reaches the end point of the rolling element rolling path 13, it is scooped up from the rolling element rolling path 13 by a rolling element scooping projection 39 described later and sent to the curved path 16. The rolling element 3 entering the curved path 16 makes a U-turn and is introduced into the linear path 14, and reaches the curved path 16 on the opposite side through the linear path 14. Here, the U-turn is performed again to return to the starting point of the rolling element rolling path 13, and such circulation in the rolling element circulation path 13 is repeated infinitely.

Here, the end cap 2B (particularly the back surface) will be described in more detail. As shown in FIG. 4, the semicircular upper concave portion 31 and the lower concave portion 32 that are inclined obliquely correspond to the upper and lower sides of the left and right arms 6, 6 on the contact surface (back surface) with the slider body 2 </ b> A. In addition, a semi-cylindrical concave groove 33 is provided across the center of both semicircular concave portions 31 and 32.
The semi-cylindrical concave groove 33 is fitted with a semi-cylindrical return guide 35 (see FIG. 5) obtained by, for example, injection molding of a resin material. FIG. 6 is a perspective view of the end cap 2B to which the return guide 35 is attached. On the outer diameter surface of the return guide 35, concave grooves 36, 36 having a circular arc cross-section serving as the guide surface of the rolling element 3 are formed in a semicircular shape, and the concave portion 37 on the inner diameter side of the return guide 35 is provided with a lubricant. A through hole 37a that is a passage and extends from the concave portion 37 to the concave groove 36 on the outer diameter side is formed as an oil supply hole.

  By incorporating such a return guide 35 into the semi-cylindrical concave groove 33, a circular doughnut-shaped curved path 16 having a circular cross section is formed in two steps on the left and right sides of the back surface of the end cap 2B (see FIG. 3). When the end cap 2B is attached to the slider body 2A, the rolling elements rolling paths 13 and 13 and the linear paths 14 and 14 are communicated with each other by the curved paths 16 and 16.

  In the end cap 2B, a rolling body scooping protrusion 39 that is projected in a semicircular shape is formed at the inner end of the curved path 16 that guides the rolling element 3, and an acute-angle tip of the rolling end of the guide rail 1. It arrange | positions so that the groove bottom of the moving body rolling groove | channel 10 may be adjoined. The rolling element 3 is scooped up from the rolling element rolling path 13 and sent to the curved path 16 by the rolling element scooping protrusion 39 provided in the end cap 2B.

  Further, for example, an end cap 2B of the slider 2 is provided with an oil supply nipple 22 as a lubricant inlet. Lubricants such as grease and lubricating oil injected from the oil supply nipple 22 on the front side of the end cap 2B pass through the oil supply passage 21 made of a groove formed on the back surface of the end cap 2B and from the concave portion 37 on the inner diameter side of the return guide 35. It passes through the through hole 37a and is fed into the curved paths 16 on both the left and right sides. Then, the lubricant is carried by the rolling element 3 to reach the rolling element rolling path 13 from the curved path 16 so that the rolling element 3 is lubricated.

  Such a linear motion guide device is provided with a valve 40 that adjusts the amount of lubricant supplied at an intermediate position in the oil supply passage 21. That is, as shown in FIG. 7, an oil supply port 23 extending from the front-side oil supply nipple 22 opens at a substantially central position in the left-right direction on the back surface of the end cap 2B. The extending oil supply paths 21 and 21 communicate with the left and right curved paths 16 and 16, respectively. A valve 40 is provided at each midway position of the left and right oil supply paths 21 and 21 (a position downstream of the oil supply nipple 22 and between the oil supply port 23 and the curved path 16). The amount of lubricant flowing through 21 is adjusted. Therefore, the amount of lubricant sent to the rolling element rolling path 13 via the curved path 16 is adjusted by the valve 40.

  The structure and operation of the valve 40 will be described in detail below with reference to FIGS. First, the valve 40 will be described. The valve 40 is made of an elastic material. When the pressure acting on the valve 40 is a predetermined value or more, the valve 40 is elastically deformed to be in an open state, and when the pressure is less than the predetermined value, the valve 40 is in a closed state. When the valve 40 is in an open state, the lubricant in the upstream portion of the valve 40 in the oil supply passage 21 passes through the valve 40 and flows downstream. The degree of deformation of the valve 40 increases as the pressure increases, and the degree of opening of the valve 40 increases. Accordingly, the amount of lubricant passing through the valve 40 is automatically adjusted according to the height of the pressure, and a larger amount of lubricant passes through the valve 40 as the pressure increases.

  The shape of the valve 40 is not particularly limited as long as it has such a function. For example, the shape shown in FIG. 8 is preferable. That is, a substantially I-shaped cross section in which flange-shaped fixing portions 42 and 42 are formed at both longitudinal ends of the flat deformed portion 41 is preferable. The valve 40 having a substantially I-shaped cross section is fixed to an oil supply passage 21 formed on the back surface of the end cap 2B as shown in FIG. That is, the fixed portions 42 and 42 of the valve 40 are attached to the inner surface of the oil supply passage 21 so that the deformed portion 41 of the valve 40 completely closes the oil supply passage 21.

  Therefore, as shown in FIG. 9, even if the lubricant L is introduced from the oil supply nipple 22 as indicated by the arrow, the deformed portion 41 of the valve 40 as long as the pressure received from the introduced lubricant L is less than the predetermined value. Is not deformed, the valve 40 is closed. When the valve 40 is in a closed state, the lubricant L is blocked by the valve 40 and is filled in a portion of the oil supply passage 21 between the oil supply nipple 22 and the valve 40.

  However, as shown in FIG. 10, when a large amount of lubricant L is introduced from the oil supply nipple 22 and the pressure received from the introduced lubricant L exceeds the predetermined value, the deformed portion 41 of the valve 40 is used. Is elastically deformed according to the pressure received from the lubricant L, so that the valve 40 is opened. That is, the side part 41a is fixed to the inner surface of the oil supply passage 21 and the side part 41b is not fixed to the inner surface of the oil supply passage 21, and thus is fixed. The non-side side portion 41b bends to the downstream side by the pressure of the lubricant L, and a gap (that is, an opening) is formed between the side portion 41b of the deformable portion 41 and the inner surface of the oil supply passage 21, and an arrow in FIG. As shown, the lubricant L flows downstream from this opening. However, the both side portions 41a and 41b of the flat deformed portion 41 may not be fixed to the inner surface of the oil supply passage 21, and the both side portions 41a and 41b may be bent downstream by the pressure of the lubricant L.

  When the lubricant L flows downstream from the opening of the valve 40 in the open state, the amount of the lubricant L in the upstream portion of the valve 40 in the oil supply passage 21 decreases, and the pressure received by the valve 40 from the lubricant L Will decline. When the pressure of the lubricant L in the upstream portion of the valve 40 in the oil supply passage 21 becomes less than the predetermined value, the deflection of the side portion 41b of the deformed portion 41 of the valve 40 returns, and the valve 40 The deforming portion 41 has an original shape. Then, since the valve 40 is in a closed state, the flow of the lubricant L to the downstream side is blocked.

The higher the pressure, the more the side part 41b on the non-fixed side bends and the degree of opening increases, so the amount of lubricant L passing through the valve 40 also increases. Since the amount of bending of the deforming portion 41 of the valve 40 is determined by the height of the pressure, the amount of the lubricant L passing through the valve 40 is automatically adjusted by the height of the pressure.
The linear motion guide device may be installed in an inclined posture in which a height difference is generated between the rolling element rolling paths 13 on the left and right sides, but the valve 40 as described above is provided in each oil supply path 21. Since the amount of the lubricant L automatically adjusted by the pressure passes through each valve 40 regardless of the height difference, almost the same amount of the lubricant L is applied to the rolling elements on the left and right sides. It will be supplied to the flow paths 13 and 13.

  Therefore, even when the linear motion guide device is installed in an inclined posture in which a height difference is generated between the rolling element rolling paths 13 on the left and right sides, the rolling element rolling paths on the left and right sides are installed. The difference in the amount of lubricant supplied to 13, 13 hardly occurs. Further, even when the guide rail 1 is installed along the vertical direction, or when the guide rail 1 is installed upside down (the guide rail 1 is disposed on the upper side and the slider 2 is disposed on the lower side). The supply of the lubricant L to each rolling element rolling path 13 is stably performed without any problem.

In addition, since such a valve 40 has a simple mechanism for adjusting the amount of lubricant as described above, in addition to being able to be manufactured at a low cost, malfunction of the adjusting mechanism is unlikely to occur. Such a mechanism for adjusting the amount of lubricant by the valve 40 can be applied regardless of whether the lubricant is lubricating oil or grease.
As described above, the amount of the lubricant L passing through the valve 40 is automatically adjusted by the pressure, but the pressure at which the deformation of the valve 40 starts to occur due to a change in the shape or material of the valve 40 (the predetermined value). Value) and the amount of deformation of the valve 40 at a predetermined pressure changes, so that the predetermined value becomes a desired value, and the pressure of the lubricant L and the amount of the lubricant L passing through the valve 40 The shape and material of the valve 40 may be set so that the above correlation becomes a desired correlation. The material of the valve 40 is not particularly limited as long as it does not cause deterioration, damage such as dissolution, swelling, deformation, etc. due to contact with the lubricant L, but resin, rubber, metal and the like are suitable.

  Further, although the inner diameter of the oil supply passage 21 may be constant throughout, as shown in FIGS. 9 and 10, a step is provided in the inner diameter of the oil supply passage 21, and the deformed portion 41 of the valve 40 is formed on the end surface 21a forming the step. You may fix the valve 40 so that the side part 41b may contact | connect. With such a configuration, even if the lubricant L flows backward and pressure is applied to the deformed portion 41 of the valve 40 from the downstream side to the upstream side, the side portion 41b of the deformed portion 41 of the valve 40 is connected to the end surface 21a. , It is prevented from bending to the upstream side. Therefore, the lubricant L that has flowed back does not flow upstream through the valve 40, and therefore the lubricant L does not flow into the rolling element rolling path 13 on the opposite side.

For example, the linear motion guide device is installed in an inclined posture in which a height difference is generated between the rolling elements rolling paths 13 on the left and right sides, the rolling elements rolling path 13 on the left side is high, and the rolling elements rolling on the right side. Assume that the road 13 is arranged low. Then, there is a possibility that the lubricant supplied to the rolling element rolling path 13 on the left side of the higher side may move downward due to gravity, but if the backflow is prevented by the valve 40 as described above, the higher side The lubricant does not flow from the left rolling element rolling path 13 to the lower right rolling element rolling path 13. Therefore, since the lubricant is stably supplied also to the higher-side rolling element rolling path 13, there is almost a possibility that a shortage of lubricant occurs in the higher-side rolling element rolling path 13 and problems such as seizure occur. Therefore, the linear motion guide device has a long life.
In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, the lubricant amount adjusting mechanism including the oil supply passage 21, the valve 40, and the like is provided in the end cap 2B, but may be provided in the slider body 2A.

DESCRIPTION OF SYMBOLS 1 Guide rail 2 Slider 2A Slider main body 2B End cap 3 Rolling body 6 Arm part 7 Flat plate part 10 Rolling body rolling groove 11 Rolling body rolling groove 13 Rolling body rolling path 14 Linear path 16 Curved path 17 Rolling body return path 21 Oil supply path 21a End face 22 Oil supply nipple 23 Oil supply port 40 Valve 41 Deformation part 41b Side part L Lubricant

Claims (3)

A guide rail having a rolling element raceway surface extending in the axial direction; a slider having a rolling element raceway surface opposed to the rolling element raceway surface of the guide rail and attached to the guide rail so as to be relatively movable in the axial direction; A plurality of rolling elements arranged in a rolling element rolling path formed between the rolling element raceway surface of the guide rail and the rolling element raceway surface of the slider, and introduction of a lubricant provided in the slider An oil supply passage for supplying the lubricant introduced from the opening to the rolling element rolling passage, and a valve provided at a position downstream of the lubricant introduction port in the oil supply passage,
The valve is opened when the pressure of the lubricant introduced into a portion of the oil supply passage between the lubricant inlet and the valve is equal to or higher than a predetermined value, and allows the lubricant to pass downstream. In addition, the higher the pressure, the greater the degree of opening ,
The valve is made of an elastic material, and the valve is elastically deformed and opened by the pressure, and the degree of deformation of the valve increases as the pressure increases, and the degree of opening of the valve increases. We have been,
The shape of the valve is a substantially I-shaped cross section in which flange-shaped fixing portions are formed at both ends in the longitudinal direction of a flat plate-like deforming portion that is deformed by the pressure, and the deforming portion that is not deforming the oil supply passage. The linear guide device characterized in that the both fixing portions are attached to the inner surface of the oil supply passage so that the valve is fixed to the oil supply passage so as to be completely closed . The linear motion guide device according to claim 1, wherein at least one side portion of both side portions of the deformable portion is not fixed to an inner surface of the oil supply passage. The linear motion guide according to claim 1 or 2, wherein a step is provided in an inner diameter of the oil supply passage, and the valve is fixed so that a side portion of the deformable portion is in contact with an end surface forming the step. apparatus.

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